Effect of interactions of biomass constituents on polycyclic aromatic hydrocarbons (PAH) formation during fast pyrolysis

• Interaction of cellulose, hemicelluloses & lignin during pyrolysis are reported.
• Interactions of cellulose and lignin increase gas & residue and decrease tar.
• PAH concentrations are increased due to interaction of xylan and cellulose.
• However, PAH are decreased due to interaction of xylan and lignin.

The interactions of biomass constituents (hemicellulose, cellulose and lignin) were investigated during fast pyrolysis at 800 °C in a fixed bed reactor. The formation of polycyclic aromatic hydrocarbons (PAH) as well as mass distribution and gas products is presented. The possible interactions of biomass constituents were compared with the results of the expected results based on the pyrolysis of single components. For the interaction of xylan and cellulose, the mass distribution was similar to that expected from calculation of single component addition, however, PAH were increased. The interaction of xylan and lignin produced a decrease in PAH concentration compared to that expected from single component data. There was evidence of strong interaction between cellulose and lignin, where gas and solid residue yield was decreased and tar/oil yield was increased. In addition, naphthalene, acenaphthylene, and chrysene/benzo[a]anthracene were decreased compared with the concentrations expected from the single component pyrolysis. However, the amounts of 1-methynaphthalene, 2-methynaphthalene, acenaphthene, fluorene, phenanthrene, anthracene, and pyrene were increased.